Seed abuse reports

What does this MR do?

Seed your dev DB with abuse reports

rake db:seed_fu FILTER=abuse_reports

Are there points in the code the reviewer needs to double check?

Why was this MR needed?

Useful for testing abuse reports such as this situation https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/9233

Screenshots (if relevant)

Does this MR meet the acceptance criteria?

• Changelog entry added
• Tests
  • All builds are passing
• Conform by the merge request performance guides
• Conform by the style guides
• Branch has no merge conflicts with master (if it does - rebase it please)
• Squashed related commits together

What are the relevant issue numbers?

Thanks to @stanhu for the details https://gitlab.com/gitlab-org/gitlab-ce/issues/28059#note_23325328